To date, aberrant regulation of the JAK1/2-STAT6 pathway has been identified in different pathological conditions [9] and activated STAT6 has been found in patient samples isolated from Hodgkin lymphomas [10,11], cutaneous T cell lymphomas [12], adult T cell leukemia and B-lymphomas [13,14]. Here, STAT6 is linked to adult T-cell leukemia/lymphoma.